Exhaust machine chuck



Oct. 6, 1959 s. J. GARTNER EXHAUST MACHINE CHUCK 3 Sheets-Sheet 1Original Filed Deo. 24, 1946 j INVENTOR. r'jSTANLEY J. GARTNER BY y jf/w/@W Oct. 6, 1959 s. J. GARTNER 2,907,141

E1n-MUST MACHINE CHUCK Original Filed Deo. 24, 1946 3 Sheets-Sheet 2 INV EN TOR.

STANLEY .1. GARTNER Oct. 6, 1959 s. J. GARTNER 2,907,141

EXHAUST MACHINE CHUCK Original Filed Dec. 24, 1946 I5 Sheets-Sheet 3 IIE m, @n /M/-l United States Patent() 2,907,141 EXHAUST MACHINE CHUCKStanley J. Gartner, Emporium, Pa., assignor, by mesne assignments, toSylvania Electric Products, Inc., Wilmington, Del., a corporation ofDelaware Original application December 24, 1946, Serial N0. 718,152, nowPatent No. 2,661,576, dated December 8, 1953. Divided and thisapplication October 14, 1953, Serial No. 394,587

7 Claims. (Cl. 49-64) This invention relates to the manufacture of radiotubes and like devices.

This application is a division of application Serial No. 718,152, tiledDecember 24, 1946, which matured into U.S. Patent No. 2,661,576 ofDecember 8, 1953.

Among the objects of the invention are to provide: new and useful chuckssuitable for spindles in processing apparatus; an improved form of chuckfor gripping a glass exhaust tube; a chuck for reliably gripping brittlearticles with a minimum of impact; a pair of coaxial chucks to grip apair of assembled parts with the supporting and operating mechanism ofboth chucks located at the same end of the parts assembly; a chuck thejaws of which may be interposed in the path of flames without impairingthe uniform heating of the parts gripped; and an organization, havinggenerally improved features, for making a glass seal between a pair ofcylindrical parts.

The illustrative embodiment of the invention i-s for sealtogether ashell and a mount to constitute an unevacuated envelope encasingelectrodes in a well-known process of manufacturing radio tubes and thelike devices. In this process the shell is usually a glassv cylinderclosed at one end, although it may be of metal having 'its edge preparedfor a glass seal; and the mount is made up of a cupped or flat glassheader larger enough to close the open end of the shell, a number ofmetal leads extending perpendicularly through the header, the electrodesor mount assembly supported on the leads above the header, and anexhaust tube extending centrally from below the header. 'Ihe unitcomprising the exhaust tube, the header and the metal leads, before themount assembly is attached, is termed the stem, although the entireassembly after the mount assembly is attached is frequently called thestem (rather than the mount as defined above). In describing theillustrative embodiment of the invention the terms mount and stem areused interchangeably.

In prior art sealing machines there were multiple spindles eachcomprising a stem chuck and a shell chuck, the stem chucks beinglcarried by a turret and the shell chucks being axially aligned with thestem chucks and carried from a ponderous superstructure, to expcse theopposed shell and stem edges to the sealingames. It is a further objectof the present invention to eliminate the superstructure, for manyattendant advantages, without impairing the proficiency of the sealingmachine.

Further features of novelty and objects will be apparent from thefollowing detailed disclosure of a preferred embodiment of the inventionwith reference to the attached drawings, wherein:

Fig. 1 is Va plan view of a spindle comprising coaxial chucks embodyingthe invention;

Fig. 2 is a sectional view along the line 2 2 of Fig. l illustrating apreferred form of exhaust-tube chuck;

`Fig. 3 is a longitudinal sectional view along the line 3-,-3 of Fig. 1;

` Fig. 4is a fragmentary plan view of the machine;

' Fig. 5 is a sectional view along the line 5-5 of Fig. 3;

Fig. 6 is a detailed `view of a mechanism for recipro- 2,907,141VPau-.med oci. e, 1959 ice , and ilanged at their lower ends, so thatFig. 7 is a fragmentary sectional view similar to Fig. 3, with the partsshown in their configuration at the time of release of the fusedenvelope;

`Fig. 8 is an enlarged detail view of a portion of the mechanism of Fig.2;

Fig. 9 is a timing chart; Fig. 10 is a sectional view along the line10--10 in Fig. 7; and

Fig. 11 is a fragmentary lateral view of a spindlel showing a modifiedformof shell chuck jaws.

Referring now to the drawings, the preferred forms' of envelope chuck,exhaust-tube chuck, and the arrangement of these two chucks in relationto each other and to their operating mechanisms will be described. The

` assembly of chucks and their supports are mounted forj rotation, andconstitutes a spindle.

In Figs. 1 and 3 shell S is shown centered on the spindle by means ofthree jaws 10. The shell is held in axialr alignment with a stem(comprising header H, exhaust tube T, external pins, and a mountassembly within the shell) lso that ame from burner B may soften theopposed edges of the header and the shell to form a sealed envelope. Theheader is supported and the exhaust tube is gripped on the spindle whichis intermittently indexed with turret 11 (Fig. 4). At most positions ofthe turret each spindle is rotated about its axis.

Rotation of each of the spindles is effected by means of the usualfriction clutch 12 which is engaged with pinion 14, maintained inrotation when the spindle is in the tiring positions by means of a chain16 (Figs. 3 and 4). Clutch 12 is secured to drive a generally tubularmember 18 which is carried in the turret by means of bushing Z0. Pinion14 is rotatable on member 18. With pinion 14 in rotation, clutch 12 isarrested under certainV circumstances, to lock the spindle, by a latch(not shown) adjacent the turret. Above the turret is a bearing block 22for each of the spindles through which lubrication may be supplied tothe respective member-s 18 by oil cups 24. Bushings 20 are externallythreaded at their upper ends they can be locked to the turret bycastelated nuts 26, thus clamping blocks 22 in place.

Each member 18 has an annular rib 30 supported on washer 28 abovebushing 20, and contains a shaft 31 for supporting header H and foroperating the gripper for exhaust tube T. Above each rib 30 there is amechanism for supporting and operating jaws 10 for the shells.

Shell chuck jaws 10 are supported from below and, in one form aremodified4 construction the jaws bowed outward, resembling questionmarks, contacting the shell S at their upper extremities. Anintermediate portion 10b of each jaw 10 is transversely streamlined atthe level of the burners B by being tapered in opposed directions, thatis, in the direction toward the liame and the direction away from theflame (Fig. l0), for uniform heating of the glass edges and (later) theseal. But for this streamlining jaws 10 might form a baille at threeparts of the seal opposite the three jaws shown. In 10a are streamlinedbut 3 not bowed (Fig. ll). In both forms of the invention, thestreamlining is achieved by relieving away or cutting away corners ofthe intermediate portions of the jaws whereby the jam cross section ofthe jaws is reduced to present minimal obstruction to exposure of thearticle toame.

Two of the jaws have two points at which they Contact shell lS whereasthe third has but a single point of cont-act. In this way the two-pointjaws form a sort of vertical cradle for supporting shell S against thepressure applied by the single-point-of-contact.jaw when all three jawsare pressed toward each other.

Jaws 10 are supported on blocks 32 for vertical adjustment byl means ofscrew 34 in block 32. Each of the jaws is slotted at 36 to vaccommodatethis screw, and each of the jaws is contined within a vertical groove inblock 32 (Fig. 5).

.laws 10 are so supported and operated as to allow the header support toraise the radio tube with its complete seal into a position of clearancefor removal (Fig. 7) and toallow renewed loading of a stem and of ashell thereon. The assembly is then lowered properly within jaws 10 andthe shell is gripped. According to the present invention the shell jawsare supported and operated from below in such manner as to cause them toapproach radially and without any pivotal swing toward the spindle axis.This is an important consideration, for with appreciable swing the jawswould develop considerable momentum. This would result in hazardousimpact when the jaws engage shell S which commonly is of glass. Thesupport and operating mechanism to be described is provided so that thejaws may be controlled' from a position not merely below their point ofengagement with the shell S but also below the level of burner B.

Each block 32, which carries its jaw 10, is mounted for substantiallyhorizontal shifting on pairs of leaf springs 38, these leaf springsfunctioning as a parallel linkage to restrictl jaws 10 against pivotalmotion, and to restore jaws 10 to the position in Fig. 7 when releasedby the operating mechanism. At their lower extremities springs 3 8 aresecured to a control means biasing the jaws radially inward andreleasing them for movement radially outward, which will now bedescribed. There is provided a support 40 for the springs 38 which is,in turn, secured to rotary tubular member 18 by means of a set-screw 42(Fig. 2). Y

Support 40 pivotally carries a coupling means including one lever 44 foreach of the three jaws 10. At its upper end each lever 44 contacts adepending portion 46 of block 32. At its lower end each lever 44 carriesan adjustment screw 48 and lock nut, which screw transmits thrust fromarm 50 to lever 44 and the jaws 10. The coupling means further includesthree arms 50, one for each lever 44, supported on reciprocable ringmember 52 which is slidable along tubular member 18 and is normallydepressed against rib 30 by compression spring 54. Reciprocable ringmember 52 is restricted against rotation with respect to member 18 bykey S6 (Fig. 2) coniined within opposed keyways in ring 52 and member18. The reciprocable ring member 52 of each of the spindles is groovedat 58 for snug engagement by yoke 60 (Figs. l, 3, 4 and 7), clamped tothe upper end of a slide 62 in the form of a slidable rod at the lowerend of which is a socket and an anti-friction ball 66. This rodl isslidable in lubricated bushing 64 which is clamped within a slotted borein block 22.

l In operation, the spindles are carried intermittently 1n a circularpath around the machine from one station to another. They are rotatedcontinuously, except at the loadmg and unloading stations. In the courseof this travel of the spindles, all of the slides 62 are carried above astationary cam-track 68 on the machine base (Figs. 4 and 9). Normally,as shown in Fig. 3, slide 62 is left unsupported at its lower extremity,and compression spring 54 in addition to the weight of ring 52, yoke 60and slide 62 causeV arm 50 to swing counterclockwise (compare Figs. 7and 3) thereby pivoting lever 44 counterclockwise, and moving all threejaws 10 into contact with shell S. This motion occurs just ascamfollower 66 drops off cam 68 (Fig. 9). The spring and weight assemblycauses rm engagement of the jaws with shell S, yet resiliency of theleaf springs and the jaws accommodates variations in the diameter ofthe. shell. .laws 10 move through a relatively short path into contactwith the shell, the upper ends of the jaws traveling the same distanceas blocks 32 and in aparallelpath. The impact of the jaws as theycontact shell S is vastly reduced as compared to the impact of anypractical form of jaws which move pivotally toward the shell.

When slide 62 is raised, leaf-springs 38 move jaws 10 radially outwardto release the shell.

Stem chuck and' support Header H is supported on a ring 70 Awhich formspart of an adapter 72 secured by set screw 7 4 to theV upper end ofinnermost tube 31 of the spindle. Ring 70 is spaced from the body ofadapter 72 by three legs 78, whereby preheating and cooling gases may bedirected against the bottom of header H. Exhaust tube T is protectedagainst these gases by tubular bale which rests on the top of tube 31,and forms part of the adapter. Certain aspects of this adapter aredisclosed and claimed in copending U.S. application Serial No. 693,146,tiled August 26,( 1946, by Clayton R. Cowley, which matured into U.S.Patent No. 2,484,688 of October ll, 1949.

Tube 31 is slotted radially near its top at three points, to accommodatean equal number of grippers 81 (Fig. 5). Each slot (one of which isindicated at 83 in Fig. 8), has a greater axial extent at the outsidesurface of tube 31 than along its bore 84, thus forming a step 181.Extensions 82 on grippers 81 falling against a step such as 181 limitthe inward movement of the grippers so that they cannot fall into thebore of tube 31. A sleeve 86 is slidable along tube 31 and surroundsgrippers 81. Sleeve 86 is externally shouldered at 88 to provide abearing surface against which compression spring 90 may act so asnormally to urge sleeve 86 upward. Spring 90 reacts against a cup 92keyed against rotation and resting on a shoulder of tube 31. Sleeve 86has an internal shoulder 94 (Figs. 5 and 8). Between shoulder 94 and aV-shaped recess r96 in each gripper 81 there is an interponent 98. Whenspring 90 is allowed to elongate, the interponent 98 of Fig. 8 isrotated clockwise into a more-or-less horizontal position, forcing theassociated gripper 81 radially toward exhaust tube T. The other twogrippers are simultaneously moved toward tube T. Sleeve 86 is limited inits upward travel by the setting of adapter 72. Nevertheless, in theevent that the adapter is removed for substitution, sleeve 86 will beprevented from unintentionally sliding olf the end of tube 31 by thecoaction of interponents 98 with grippers 81, and by these in turn.

with radial slots in tube 31.

Tube 31 is provided with a keyway 99 (Fig, 5 )1 for key 100, and thiskey is constrained to move axially with sleeve 86 by virtue of extension104 just underneath sleeve 86. Overhanging portion 102 (Fig. 2) on key100 is.

adapted to rest on shoulder 94 and arrest upward movement of sleeve 86at a predetermined point in its travel. Keyway 99 extends axially alongtube 31 to a point somewhat below rib 30. Key 100 similarlyiextendsdownward along tube 31 and has another lateral extension 106.l

Tube 18 is relieved at its upper end (Fig; 2) .to accommodate a stop 108which extendsV fromV fixed ring 40 into keyway 99 so as to limittheupward travel oflateral extension 106.

The operation of jaws 10V has beenA described above.l

It will be recalled that, during the portion of the-cycle when theheader and the envelope are to bevloaded intothe upper end ofthe-spindle, as well as when 'the .fused product is to be removed, slide6 2 iselevatedto'raise the reciprocable ring member 52 for opening jaws10 tothe necessary extent, The parts are shown in this configurak tionin Fig. 7, from which it will be apparent that jaws remain at a constantlevel. While jaws 10 are open it is so arranged that the grippers 81 forexhaust tube T shall be released for movement radially outward, andadapter 72 shall be raised considerably relative to jaws 10 tofacilitate loading and unloading operations. The mechanism describedabove for operating grippers 81 causes engagement thereof with exhausttube T as soon as adapter 72 and its supporting tube 31 have commencedtheir descent, and maintains this engagement until the processing hasbeen completed and elevation of tube 31 is nearly complete.

Tube 31 is provided with a keyway 99 (Fig. 5) for key during the'initialandthe nal portions of the cycles. This is effected by the engagement ofadjustable cam follower 110, screwed to the lower end of tube 31, withstationary cam track 112 (Figs. 3, 4 and 9) on the machine base. So longas cam follower 110 remains opposite a low portion of cam 112 spring 90is free to force sleeve 86 relatively upward and cause engagement ofgrippers 81 with exhaust tube T. However, when tube 31 is raised, key100 is carried with it until lateral extension 106 is arrested by stop108.V This arrests the continued upward movement of sleeve 86 becauseportion 102 butts against shoulder 94. The relative motion betweensleeve 86 and ascending tube 31, releases grippers 81 to permit removalof the fused envelope and insertion of a new header H with its exhausttube T. Tube 31 is permitted to rise a distance d (Fig. 2) while firmlygripping the exhaust tube and similarly to descend distance d with theexhaust tube gripped. When tube 31 is forced above this limit theexhaust-tube chuck is opened to release or receive an exhaust tube.

The exhaust tube chuck described has several important advantages. Sinceit is independent of any large mass for operation, its operation isrelatively free of the shocks which are to be expected from the suddenapplication of a gripper-operating weight which characterizes comparableprior art mechanisms. The gripper described so operates as toaccommodate exhaust tube irregularities, yet it grips firmly, and it iseffective during the fast vertical travel of the article support. Inthis way it maintains the header H properly seated on adapter ring 70for alignment with the burners, against inertia effects duringreciprocation of tube 31. In pursuing my objective of supporting theshell chuck 10 from below, I have provided the header support with along stroke, and I have devised an exhaust-tube chuck or gripper that iseffective after the initial descent of the adapter and until the nalpart of its subsequent ascent.

Cycle of operations Referring now to Fig. 9 the complete cycle ofoperation of the sealing machine will be described. The timing chartshown there is divided into 16 intervals, whereby each of 16 spindlesmay in stepwise succession be positioned at any given processingstation. The timing chart actually shows the contour of the stationarycam tracks mounted on the machine bed along which cam followers 66 and110 are moved by the spindle-supporting turret. During the travel of thespindle from the first to the second station in Fig. 9, jaws 10 andgrippers 81 remain retracted and adapter 72 is elevated above jaws 10.During this interval the spindles do not rotate. Header H may beinserted, and shell S may be placed above the header which at thisstageof manufacture carries the internal electrode assembly of the radio tubeor like device. During the transit of any given spindle from the secondto the third station, cam-follower 110 travels along cam surface 112,initially causing grippers 81 to engage exhaust tube T, and thenlowering the shell-and-header assembly into position for engagement byjaws 10. At the third station, by virtue of the shape of cam 68whichoperates cam-follower 66, jaws 10 are moved rmly but with-a minimumof impact into engagement with shell S to center the shell roughlyon'header H. Thereafter, during thek indexing operation from the thirdto the fourth station, jaws 10 are opened, then closed again, andfinally adapter 72 is raised very slightly so as to press header Hfirmly into abutment with shell S. When shell S is thus held at adefinite level by closed jaws 10, the stem chuck-andsupport 31 isallowed to drop slightly between stations 4 and 5 to space shell Sslightly above header H. Rotation of the spindles and ring are thencommenced. By virtue of key 56 (Fig. 2) drive is transmitted not only toring 52 but also to shaft 31, having a keyway therein, for driving thetwo chucks in perfect synchronism. 'I'his is an additional advantage ofsupporting both chucks from one end of the shell-and-stem assembly.

From the fth station until the twelfth, various burners are brought tobear on the edges of the shell and the header so as to preheat them andultimately to fuse their edges. Preheating llames are optionally broughtto bear on the bottom of header H, to minimize internal strains. By thetime any spindle reaches station 13 the edges of shell S and header Hhave already been fused. Roller 114 reciprocates vertically under camfollower of the header support, thereby to move the fused edge of theheader into contact with the soft edge of the shell, form ing the seal,and promptly thereafter to allow cam follower 110 to drop so as tostretch the seal. This reciprocation is of the order of 1/16 of an inch,and is achieved by the mechanism in Fig. 6. Roller 114 is carried at oneend of lever 116 which is pivoted at its center and at its opposite endby turnbuckle 118 constituting an adjustable link between lever 116 andcam follower 120 of rotary cam 122. During those intervals when theturret is at rest with a spindle at station 13, cam 122 is rotated onceto make the seal and to stretch the seal.

During thetravel of a spindle from station 13 to station 1S, the seal isallowed to cool. A rise in cam 68, between stations 14 and 15 causesjaws 10 to be retracted from shell S. Thereafter the sealed envelope iscarried upward rapidly, and during the slow, final elevation of adapter72, exhaust tube grippers 81 are released to allow remo-val of theproduct.

The chucks described cooperate to constitute the spindle of an improvedsealing machine, but it will be recognized that they may also beseparately useful in other sealing machines and in other combinations.

What I claim is:

1. A chuck including a number of radially movable jaws and a number ofpairs of parallel radially spaced leaf springs, each of said jaws beingcarried jointly by a pair of said springs.

2. A chuck including a number of radially movable jaws, a number ofpairs of parallel radially spaced leaf springs, and means including an4axial slide for moving said jaws radially, each of said jaws beingcarried jointly by a pair of said springs.

3. A rotatable chuck adapted to support an article in position forexposure to llame comprising a plurality of axially extending jaws, eachof said jaws having an article engaging portion at one end thereof, asupport at the other end of each of said jaws, the intermediate portionsof each of said jaws having a cross-section which is tapered in opposeddirections for presenting minimal obstruction to exposure of saidarticle to llame.

4. A rotatable chuck adapted to support an article in position forexposure to ame comprising a plurality of axially extendingjaws eachhaving a radially extending intermediate portion of substantiallyrectangular cross section, each of said jaws having an article engagingportion at one end thereof, a support at the other end of each of saidjaws, said intermediate portion of each of said jaws having across-section tapered in opposed direction for presenting nominalobstruction to exposure of said article to flame.

axially extending jaws, each of said jaws having an article engagingportion at one end thereof, a support at the other end of each of saidjaws including a pair of parallel leafV springs, the intermediateportion of each of said jaws having a cross-section tapered in opposeddirections for presenting nominal obstruction to exposure of saidarticle to flame.

6. A chuck for supporting an elongated article comprising a plurality ofjaws each movable radially of and at right angles to the longitudinalaxis of said article, a mount for each of said jaws including verticaiiyextending leaf springs arranged parallel to each other and to saidlongitudinal axis, and means operative to advance said jaws intogripping relation to said elongated article and arranged to allow forperiodic retraction of said jaws from gripping relation to said article,said means including a slide movable through a prescribed thrust, areciprocable member operatively connected to and displaceable by saidslide, an arm mounted on said reciprocable member for pivotal movementwhen said reciprocable member is displaced, and a lever mounted forrocking movement and normally in iurged engagement with and deformingsaid leaf springs for biasing said jaws into gripping relation to saidelongated article, said lever being controlled by pivotal movement ofsaid arm and rocked in a direction to release said leaf springs wherebysaid jaws retract in response to movement of said slide through saidprescribed thrust.

7. A chuck for supporting an elongated article comprising a plurality ofjaws each movable radially of and at right angles to the longitudinalaxis of said article, the intermediate portion of each of said jawshaving a cross-section which is tapered in opposed directions, a mountfor each of said jaws including vertically extending leaf springsarranged parallel to each other and to said longitudinal axis and meansoperative to advance said jaws into gripping relation to said elongatedarticle and arranged to allow for periodic retraction of said jaws fromgripping relation to said article, said means including a slide movablethrough a prescribed thrust, a reciprocable member operatively connectedto and dispiaceable by said slide, an arm mounted. on said reciprocablemember for pivotal movement when said reciprocable member is displaced,and a lever mounted for rocking movement, and normally in urgedengagement with and deforming said leaf springs for biasing said jawsinto gripping relation to said elongated article, said lever beingcontrolled by pivotal movement of said arm and rocked in a direction torelease said leaf springs whereby said jaws retract in response tomovement of said slide through said prescribed thrust.

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